The Office of Naval Research (ONR) in Arlington, Va., is negotiating a phase-two Small Business Technology Transfer (STTR) contract with Lightning Packs LLC in Strafford, Pa., to reduce the weight of a backpack able to generate electricity the company has developed, and reduce noise the backpack makes when it generates electric power.

ONR researchers are asking Lightning Packs designers to refine their design of the Suspended Load Backpack, which has the rigid frame of a normal hiking backpack, yet suspends its load from the frame on vertical springs attached to a generator. The load moves up and down as the wearer walks, which activates the generator and makes the load easier to carry.

The Suspended Load Backpack is the invention of Dr. Lawrence C. Rome, a professor of biology at the University of Pennsylvania and a Whitman Investigator at the Marine Biological Laboratory in Woods Hole, Ma.

Rome and his colleagues envision a backpack for soldiers, Marines, first responders, and even children on the way to school to help lighten loads and generate electricity for portable devices.

The Suspended Load Backpack can generate as much as 7.4 Watts of electricity when the wearer is walking -- enough to power or recharge an MP3 player, night-vision goggles or a three-LED headlamp, handheld computer, a CMOS image decoder, a handheld GPS, and Bluetooth, Lightning Packs officials say.

"As humans walk, they vault over their extended leg, causing the hip to rise five to seven centimeters on each step," Rome explains. "Since a normal backpack is connected to the hip, it must be lifted the five to seven centimeters also But with the Suspended Load Backpack, the load is not directly connected to hip, making it easier to walk and less strenuous on the back."

Enhancing the Suspended Load Backpack design is part of ONR's "Harvesting Electric Power from Walking" project.